1. Install TeXlipse from the following update site: http://texlipse.sourceforge.net/
2. After a restart, open Windows > Preferences > Texlipse/Viewer Settings and promote Sumatra to the top of the list.
3. Choose Edit. The appearing dialog is also depicted below.
4. Select the location of your SumatraPDF.exe as Viewer command
5. As Viewer arguments insert the following:
   -reuse-instance %file -forward-search %texfile %line
6. Close the dialog and re-open your document in the preview using Ctrl + 4.

Whenever you run the preview command, Sumatra PDF will jump to the appropriate position in the compiled PDF file and highlight it for a short moment.

Reference

• Solution adapted from this wiki article.
• TeXlipse homepage